Pfizer made the decision after a thorough review of data from the global, phase IIB, multicenter, randomized, double-blind, placebo-controlled, dose-ranging, eight-arm, parallel-group study of vupanorsen in statin-treated participants with dyslipidemia. The study met its primary endpoint, achieving a statistically significant reduction in nonhigh density lipoprotein cholesterol (non-HDL-C) as well as statistically significant reductions in triglycerides and angiopoietinlike 3.

However, the magnitude of non-HDL-C and triglyceride reduction observed did not support continuing the program for cardiovascular risk reduction or severe hypertriglyceridemia. Vupanorsen was also associated with dose-dependent increases in liver fat, and higher doses were associated with elevations in the liver enzymes alanine aminotransferase and aspartate aminotransferase, according to a press release from Pfizer.

Pfizer will return the development rights of vupanorsen to Ionis, from which it licensed the investigational therapy in a worldwide exclusive agreement in November 2019.